Dynamo-electric machine.



J. L. WOODBRIDGE.

DYNAMO ELECTRIC MACHINE. APPLICATION FILED MAY 20,1910. RENEWED JUNE 19, 1913.

1,084,723, Patented Ja11.20, 1914.-

lvmc Mo-r CWT- f UNITED STATES i ATENT orrion.

JOSEPH LESTER WOODBRIDGE, OF PHILADELPHIA, PENNSYLVANIA.

DYNAMO-ELECTRIC MACHINE.

1910, Serial No. 562,355.

Specification of Letters Yatent.

Patented Jun. 20. I914.

Divided and this application filed May 20.

Serial No. 774,702.

To oldie/10m it may concern:

Be it known that I, JOSEPH LESTER oonnrunon, a citizen of the United States, and a resident of Philadelphia, in the county of Philadelphia and State of Pennsylvania. have invented certain new and useful improvements in Dynamo-Electric Machines of which the following is a specification.

My invention relates to dynamo. electric machines of the alternating current type. and more particularly to constant current alternating current machines.

The object of my invention is to provide a dynamo electric machine designed to give a constant single phase current output, or. more broadly speaking, a single phase current output which will vary in proportion to the direct current excitation of the machine, and will be held constant so long as that. excitation remains constant,

The general nature and characteristic features of the invention will be more clearly understood by reference to/the following description taken in connection with the accompanying. drawing in which- I represents 'a dynamo electric machine built in accordance with my invention. It

, consists of a field frame designed in the usual manner with 4 internally projecting poles and a bi-polar wound armature K. and its commutator V. The armature is provided with single phase alternating current taps at points 34-35 which are connect ed respectively to collector rings shown conventionally in the drawing at 1 and 2. These collector rings would, of course, be mounted on the shaft in the usual manner.

By means of these collector rings current is supplied to the circuit 36-37 which supplies translating device such as are lights 5. A field winding 21 is shown on the poles of this machine connected across the circuit 2829 which is supplied with direct current by the exciter E. The winding 21 is so esigned that the current transmitted through itfrom the circuit 28-29 will produce a bipolar field in the direction of thearrow J. The brushes 3233 bear upon the commutator V at points'of maximum potential due to the field J, and these brushes are shortcircuited by conductor 48. The flow of current. through conductor 48 will produce a secondary field at ri ht angles to J. and this field will produce the voltage necessary to transmit single phase current byway of conductors 36- 3? to the translating device 5. This flow of current in th armature winding of the machine I will produce a single phase magneto-motive force in that armature. which may be divided into two components rotating about the armature in opposite directions. The rotation of the armature will hold one of these components sta lionary in space anzl the value of the single phase current output from the points 1H -33 will be such that this stationary component of the magnet-o-inotive-force will be sutlicient nearly to counter-balance that ol the field winding' 21: leaving a residuum just sutlicient to produce the flow of current across the brushes rl -fi-ll't necessary to maintain the required strength of secondary field above referred to. ()wing to the low resistance of cont'luctor {8 this residuum will be very small. and the flow of single phase current from the taps 3t 35 will be practically proportional to the excitation produced by the field winding 21, and so long as this excitation is constant the output. of single phase current from the points St -1}?) to the circuit EKG--37 will be constant. The second component of the single phase magnetomotive-force will by reason of the rotation of the armature be revolved in space at a speed double that of the armature rotation. In order to neutralize the. effect of this coniponent a stationary squirrel cage st ructure U is shown surrouinlingthe armature in close prt'iximity to its periphery. The method of constructing this squirrel cage is well known in the art. and need not be further described here. The currents induced in this squirrel cage as a result of the second component of the single phase magneto-motivc-force will be such as to practically neutralize this component leaving merely the small residuum necessary to produce these currents. The machine I is therefore a dynamo designed to give a constant current single phase. output, or broadly a single phase output proportional to its direct current field excitation.

This is a division of my application. Serial No. 490.988. filed April 20th, 1909.

Having described my invention what l claim as new and desire to secure by Letters Patent is 1. In combination an arnntture and its commutator. a field structure in inductive relation thereto. appropriate field windings for the field structure adapted to produce a magnetic field through the armature, a set of brushes bearing upon the commutator at points of potential difference due to the field, a low resistance conducting circuit connecting said brushes, a single phase consumption circuit, connected to the armature Winding, and a conducting squirrel cage structure surl'OllIKllIlg the armature close to its periphery.

In combination an armature and its con'nnLita-tor, a field structure adapted to provide a path for two sets of magnetic lines through the armature displaced from each other and constituting a primary and secondary magnetic field, windings on the field structur adapted to produce the primary field, intercminected brushes bearing on the'coninultator at points of potential difference due to the primary field and adapted to permit a fiow of current in the armature to produce the secondary field, sin gle phase terminals for the armature, a single phase consumption circuit connected thereto, and a conducting squirrel cage structure surrounding the armature close to its periphery.

In combination, in a dynamo electric machine, an armature, means for establishing a primary field there-through, means for deriving from said field and armature current for establishing in said armature a secondary field displaced from the first, connections for deriving single phase current from said armature, and a conducting circuit surrounding said armature and adapted l l l l I l l to neutralize one component of the magneto motive-force produced in the armature by said single phase current.

l. In combination, in a dynamo electric machine, an armature, means for establishing a primary field there-through, means for deriving from said field and armature current for establishing in said armature a secondary field displaced from the first, a single phase circuit connccted to said armature, and a conducting circuit surrounding said armature and adapted to neutralize one component of the magncto-motive-force produced in the armature by a fio-W of single phase current therein.

5. In combination, in a dynamo electric nulchine, an armature and its commutator. means for establishing a prii'nary field through said armature, means including a pair of brushes bearing upon the commutator and connected by an external circuit whereby a secondary field is produced through said armature displaced from the first, an alternating current circuit connected to said armature, and a conducting circuit surrounding said armature and adapted to neutralize one component of the magnetomotive-force produced in the armature by a flow of alternating current therein.

in testimony whereofl have hereunto signed my name.

JOSEPH LESTER. WOODBEIDGE.

Witnesses R. A. Wrnrrsronn, J12, CARROLL Hones. 

